Case IH 518507-03 - BCM – BCM: A/C compressor high pressure sensor - out of range - high

The signal from the A/C compressor high pressure sensor is 'out of range - high', meaning the control module is receiving a voltage or pressure value that exceeds the maximum plausible threshold. This is typically caused by a short circuit to the battery/power source in the sensor wiring, a failed sensor, or an actual extreme overpressure event in the A/C system. The system will drop out of 'auto' mode, and the A/C compressor will be locked out to prevent damage.

• MAGNUM AFS Connect
• Steiger Series 350
• Steiger Series 370
• Steiger Series 380
• Steiger Series 385
• Steiger Series 400
• Steiger Series 420
• Steiger Series 430
• Steiger Series 435
• Steiger Series 450
• Steiger Series 480
• Steiger Series 485
• Steiger Series 500
• Steiger Series 530
• Steiger Series 535
• Steiger Series 540
• Steiger Series 550
• Steiger Series 580
• Steiger Series 600
• Steiger Series 620
• Quadtrac Series 370
• Quadtrac Series 420
• Quadtrac Series 450
• Quadtrac Series 470
• Quadtrac Series 500
• Quadtrac Series 540
• Quadtrac Series 550
• Quadtrac Series 580
• Quadtrac Series 600
• Quadtrac Series 620
• Maxxum Series 140 EP
• Axial-Flow Combines 20 Series

1. 1

   Check for actual A/C system overpressure (note that simply replacing the expansion valve often does not resolve sensor-related out of range codes)

2. 2

   Inspect the high pressure sensor wiring harness for a short circuit to the battery or a circuit to ground

3. 3

   Check the sensor supply voltage from the BCM to ensure it is not experiencing a supply failure

4. 4

   Verify that the high pressure sensor connector is securely plugged into the harness and free of corrosion

1. 1

   Disconnect the electrical connector to the high pressure sensor.

   Always recover A/C refrigerant using approved equipment before opening the system.

2. 2

   Disconnect the high pressure A/C pipe from the A/C compressor.

3. 3

   Immediately install blanking plugs or caps to all openings to prevent dirt and moisture ingress.

4. 4

   Remove the faulty high pressure sensor.

5. 5

   Install the new high pressure sensor.

   When reconnecting the high and low pressure hoses to the compressor, you must install new O-rings.

6. 6

   Lubricate the new O-rings with clean A/C compressor oil before installation.

7. 7

   Secure the hoses and plug the high pressure sensor back into the wiring harness.

8. 8

   Evacuate and recharge the A/C system to the specified capacity.

9. 9

   Clear the BCM fault codes and test the A/C in both 'Auto' and 'Manual' modes to ensure the compressor engages properly.